Base and holder for electric lamps



Filed Jan. 18, 1947 lr'ivenTor- Wilber- M. Johnson,

Hus ATTor-neg.

' elongated cavity of keyhole shape.

Patented Mar. 22, 1949 BASE AND HOLDER FOR ELECTRIC LAMPS Wilber M. Johnson, Cleveland Heights, Ohio, assignor to General Electric Company, a corporation of New York Application January 18, 1947, Serial No. 722,841 13' Claims. (Cl. 176-32) My invention relates to bases and holders for electric lamps and is of particular interest in connection with double ended, elongated tubular I to and easily engageable with a holder contact.

Another object of the invention is to provide such a base and a holder therefor which permits relatively large tolerances in the length of the lamps and the spacing of the lamp holders. Further objects and advantages of the invention will appear from the following description of species thereof and from the drawing.

In the drawing Fig. l is a side elevation of a pair of lamps mounted in three spaced holders; Fig. 2 is a similar view on an enlarged scale of an end portion of a lamp showing the lamp base partly in section; Fig. 3 is a front end view of the lamp'base; and Fig. 4 is a'perspective view on a smaller scale of a double holder for accommodating two lamp bases and connecting the lamps in series.

Referring to Fig. 1 of the drawin the fluorescent lamps l are supported in aline by two single holders 2 and 3 and a double holder 4 for accommodating and making electrical connections with the lamp bases. The single holders 2 and 3 at the ends of the row of lamps may be provided with conductors for connection with terminals of a suitable electric power source and the double holder 4 connects the lamps i inseries.

The lamps l have a base at each end thereof one of which is shown in detail in Figs. 2 and 3. As shown, the base 5 comprises a shell of electrically insulating material having a skirted portion 6 for attachment to the end of the tubular glass envelope of the lamp l by basing cement l. The portion 8 of the base 5 has therein an The keyhole shaped cavity has a cylindrical part 9 extending parallel to and oifset from the longitudinal axis of the base 5 and a slot shaped part I 0 (Fig. 3) extending across the said axis and opening at the side of the base portion 8. A coiled metal spring ll is disposed in the cylindrical part 9 of the cavity and extends into the space defined by the skirt 6 of the base and the end of the lamp I. Thespring II is of such length relative to the length of the base 5 that it bears against and is compressed between the end of the lamp envelope and the end wall of the cavity part 9 when the base 5 is mounted on the lamp envelope. The current inlead wires l2 and I3 for the electrode (not shown) at the end of the envelope are inserted between the turns of the coiled spring II so as to make a goodmechanical and electrical connection therewith. Obviously, the inleads l2 and I3 may be soldered or welded to the spring H and the latter need not be compressed between the envelope and the base but may loosely fit between these members. The spring constitutes one terminal of the lamp the other terminal of which is constituted by a similar spring in a similar base mounted at the opposite end of the lamp envelope.

Access to the spring I I for connecting the lamp electrode to a terminal of a suitable source of electric power for the lamp is afforded by the aforesaid slot shaped part II] of the cavity 9.

The sides of cavity part l0 diverge outwardly from cavity part 9 to provide an outer opening it of convenient size for the-insertion of a holder contact into the base and to guide such contact into engagement with the spring H. ,For safety purposes, the size of the outer opening Hi is preferably less than. that which would-permit the insertion therein of a persons finger. This, together with the remote location of the spring II with respect to the opening M at the side of the base, gives the lamp I a high safety factor which is of particular importance with lamps requiring a relatively high open circuit voltage, such as 500 volts and higher.

As shown in Fig. 2 the opening It in the side of the base and the opening between the cavity parts 9 and H1 extend an appreciable distance longitudinally of the base. This allows for variations in lamp length and in spacing of the lamp holders. Increasing the tolerances on lamp length reduces the number of lamps rejected for being too long or too short and so reduces the cost of manufacture of such lamps. Exact spacing of lamp holders in a fixture, or on a wall or ceiling is a difiicult and time consuming task. Thus, a base which allows for variations in holder spacing facilitates mounting of the holders and reduces the cost of installing them.

The lamp holders 2, 3 and 4 for accommodating the lamp bases and supplying electrical energy to the lamp I comprise an elongated contact pin I (Figs. 2, 3 and 4) of suflicient length for insertlon through the opening l4 in the side of the base 5 and into engagement with the coiled spring II. A suitable contact pin I5 is shown mounted on one suitable type of double holder 4 in Fig. 4. The pin I5 illustrated has a pointed, cone shaped end It for facilitatin its passage between the turns of the spring II when the lamp I is placed in the holder 4 and an annular groove I'I adjoining the end IS. The base of the cone shaped end I6 and the grooved part H are larger in diameter than the distance between the turns of the compressed spring II, so that the turns of the spring II are first spread apart as the end I 6 of the pin I5 passes therebetween and then spring back into the annular groove H to grip the pin I5 after the base of the cone shaped end l6 has passed. The spring II exerts suflicient force to make a good electrical contact with pin M I5 and to hold the lamp I against the force of gravity tending to separate the lamp from its holders when the latter are mounted on a ceiling, for example. The lamp is, however, easily removable from the holder 4 by a pull in a direction transverse to the lamp axis. The Iamp I thus may be mounted on and removed from its holders by a push or a pull in a direction transverse to its longitudinal axis and without rotating the lamp about its axis.

The double holder 4 of Fig. 4 has two such pins I5 for engaging the bases on the lamps I extending therefromand is so constructed and arranged that the circuit to each pin I5 is completed by a conducting element incorporated in an electrically insulating cover I8 which must be removed from the holder 4 before a lamp base can be inserted into or removed therefrom. As shown in Fig. 4 the holder 4 comprises a main body portion I9 of electrically insulating material and defining with the two covers I8 (only one of which is shown) a pair of sockets for accommodating a base on each of two lamps. The two contactpins -I5 are partially embedded in the body IQ of the holder and project into the socket spaces 20 a suflicient distance to engage the springs II in the bases 5 when the latter are placed in the sockets. The covers I8 also consist of electrically insulating material and have the curved portion 2I of a U-shaped electrically conducting member embedded therein. The parallel legs 22 of the U-shaped member project from the cover for insertion into passages 23 provided therefor in the side walls 24 and 25 of the base 4. The two passages 23 in the side walls 25 are connected by another passage 26 which accommodates coiled spring 21 similar to the spring II in the base 5 and the two passages 23 in the wall 24 are connected to the embedded ends of the contact pins I5 by two passages 28 and 29 which likewise accommodate springs 30- and 3| of the same type. The springs 3fl and 3| are connected to the pins I5. The ends of the U- shaped conductors 2I, 22 are the same in structure as the free ends of the contact pins I5 and engage the springs 21, 3|] and 3| in the same way to hold the covers I8 and the lamp bases 5 on the holders 4.

When either or both of the covers I8 are removed for inserting or removing a lamp base 5 the series electrical connection between the contact pins I5 and including the two conductors 2I, 22 and the three springs 21, 3D and 3|, is broken; the break taking place deep within the holder 4 for safety purposes. The single holders 4 2 and 3 at the end of the row of lamps may be similar in structure to one and half of the double holder 4 shown in Fig. 4.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric lamp base comprising a. shell containing a coiled spring contact for receiving and gripping between its turns a contact of a holder for the base.

2. An electric lamp base comprising a shell containing a helical spring contact for receiving and gripping between its turns a contact of a holder for the base.

3. An electric lamp base comprising a shell having an opening in its side for receiving a contact of a holder for the base and containing a helical spring contact disposed across the opening for engaging the holder contact.

4. An electric lamp base comprising a shell having an opening in its side for receiving a contact of a holder for the base, and contact means in said shell so disposed with respect to the said opening as to engage the holder contact.

5. An electric lamp base comprising an electrically insulating shell having an opening in its side for receiving a contact of a holder for the base and having also an elongated cavity parallel to its longitudinal axis and joining said opening, and a helical spring contact in said cavity for engaging the holder contact.

6. An electric lamp base comprising an electrically insulating shell having a cylindrical cavity parallel to and ofiset from its longitudinal axis and having also an opening extending from its side, across its said axis and into said cavity for receiving a contact of a holder for the lamp base and a helical spring contact in and extending along said cavity and across the inner end of said opening for receiving and gripping the holder contact between its turns.

7. An electric lamp base comprising an electrically insulating shell provided with a skirt for attachment to the lamp and a contact enclosing portion having a cylindrical cavity parallel to and offset from its longitudinal axis and having also an opening extending from its side, across its said axis and into said cavity for receiving a contact of a holder for the lamp base and a helical spring contact disposed in said cavity across the inner end of said opening for receiving and gripping the holder contact.

8. An electric lamp base comprising a shell of electrically insulating material having a skirt for attachment to a lamp envelope and having a keyhole shaped cavity opening at its side and extending parallel to its longitudinal axis for accommodating contact means for the lamp and for receiving a contact of a lamp base holder.

9, In combination, a lamp base holder having a contact pin extending transversely into its base receiving portion and a lamp base having a keyhole shaped cavity opening at its side for receiving the contact pin and extending longitudinally of the base for accommodating contact means for engaging the holder contact.

10. In combination, a lamp base holder having a pointed contact pin provided with an annular groove adjacent its pointed end and extending transversely into the base receiving portion of the holder and a lamp base having a cavity in which is mounted a helical spring contact for receiving and gripping the pointed and recessed end portion of the holder contact between its adjacent turns, said cavity having a transversely ending portion opening at the side of the base for receiving the holder pin,

11. A lamp holder comprising an insulating housing providing a lamp socket having an electric contact, and a coiled spring conductor for the contact disposed in and supported by the walls of a cavity in the housing and exposed through a transverse opening in the housing.

aaeaioo v 6 v engaging 'a lamp terminal and separable electrical connector means in the housing for making and breaking a circuit including said contact, said connector means comprising a pin-like contact projecting from said cover into a wall of ihehousing and a coiled metal spring disposed in and supported by the walls of a cavity in the housing wall and being transverse to and gripping the pin-like contact between its turns.

- WILBER M. JOHNSON.

Resonances orrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,339,69d Douglas May 11, 1920 1,776,859. Johnston Sept. 30, 1930 20 2,149,137 Gardner Feb. 28, 1939 

